Handheld spray guns are devices that project a fine mist of fluid particles through the air and onto a substrate. A pressurized gas, such as air, is used to atomize and direct the fluid particles. High Volume Low Pressure spray guns, for example, have the advantage of reduced overspray and materials consumption and thus are preferred in a variety of commercial and industrial applications. Applications may include any of a wide variety of coating media, including primers, paints, clearcoats, slurries, fine powders, and other sprayable coating fluids. Notable applications for spray guns include painting and texturizing architectural surfaces such as walls and ceilings, furniture finishing, cosmetics, and painting and body repair for marine and automotive exteriors.
One type of spray gun uses a gun platform connected with a compressed air source and fluid passageway in communication with a spray nozzle. The air and liquid are generally directed into respective flow channels and expelled from the gun through adjacent atomizing and fluid apertures, respectively. The fast moving air flows out of the atomizing apertures through a region of reduced pressure, which in turn assists in drawing out the coating fluid from the fluid aperture and atomizing it to form a directed stream of fluid droplets.
To provide enhanced spray coverage when sweeping the spray gun over a large area, spray guns commonly incorporate a pair of air horns that receive a portion of the pressurized air supplied to the spray gun. These air horns are positioned on opposite sides of the fluid stream as it leaves the spray nozzle and have apertures (called fan control apertures) that direct air jets from opposing directions to flatten the shape of the fluid stream, thereby modifying the spray pattern achieved.